Just like speculating that soma is a mushroom, much of what scientists think they know about human development is biased speculation.
Well, I *have* come across some interesting information. The scientists in whom you seem to place so much trust didn't think that women's brains were any different from men's brains until about 15 years ago. They just assumed that they were the same.
Here's something I had posted on another forum:
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Transcribed by hand from "The Female Brain" (page 2) by Louann Brizendine, M.D. (neuropsychiatrist at UCSF, former faculty member at Harvard Medical School, and graduate of the Yale University School of Medicine and UC Berkeley):
"Until the 1990s, researchers paid little attention to female physiology, neuroanatomy, or psychology separate from that of men. I saw this oversight firsthand during my undergraduate years in neurobiology at Berkeley in the 1970s, during my medical education at Yale, and during my training in psychiatry at the Massachusetts Mental Health Center at Harvard Medical School. While enrolled at each of these institutions, I learned little or nothing about female biological or neurological difference outside of pregnancy. When a professor presented a study about animal behavior one day at Yale, I raised my hand and asked what the research findings were for females in that study. The male professor dismissed my question, stating, 'We never use females in these studies--their menstrual cycle would just mess up the data.'
The little research that was available, however, suggested that the brain differences, though subtle, were profound."